Sure, the food is rich, the booze flows freely, and those sex parties are to die for. But the distrust from fellow slaves, the resentment from the emperor’s humiliated wife and the emperor’s unwavering, adoring, smothering gaze can make life unbearable.

Such is the fate of Antinous in “Open Up, Hadrian,” a fictionalized portrait of that Roman emperor being staged at Magic Futurebox, a vast, echoing warehouse tucked into the fourth floor of a factory building in Industry City in Sunset Park, Brooklyn.

Hadrian here is an intellectually curious and sensitive emperor, more scholar than militarist. Above all, he is a lover of all things Greek — in particular (and in more or less ascending order), Greek philosophy, Greek theater and Greek men. It’s an affinity that earns him (here and historically) the questionably complimentary epithet Greekling, as well as the scorn of the barbarians in Britain, against whom he built his famous wall.

Javierantonio González’s script labors to make Hadrian sound insightful and forward-thinking, usually by knotting up his dialogue with metaphysical conversations about free will, the size of the universe and the role of theater in society.

Yet somehow Hadrian (an earnest and sometimes clothed David Skeist) is the least engaging character in this dark and meandering play. Antinous (Marcos Toledo) has more shrugs and scowls than lines — he’s more pet than confidant — but manages to hold our attention better than the leader of the unfree world.

Perhaps that’s because Antinous is allowed to be a character instead of a jumble of ideas. Likewise, Hadrian’s adoptive mother, Plotina (a hunched, slinking, chain-smoking Doris Mirescu), hijacks much of the story for herself.

Jian Jung’s industrial-chic sets (including a forest of PVC pipes) and Elizabeth Barrett Groth’s dreamlike costumes enliven a show that is sometimes swallowed acoustically and visually by the 20,000-square-foot warehouse. The director, Meiyin Wang, uses as much of the space as she can, mixing in multimedia elements, but still has difficulty stitching together Mr. González’s fragmented and capricious script.